System of electrical conductors



June 12,1928.

A. A. OSWALD SYSTEM OF ELECTRICAL CONDUGTORS fizz/en).- Arf/wrA aura/d Patented June 12, 1928.

UNITED STATES P ATENTJ orifice;

ARTHUR A. OSWA-DD,"OF BASED ORANGE, NEW JERSEY, ASSIGNOE 'IO WESTERN E530- TRICCOMPANY; INCORPORATED, OENEW YORK, N. 2., A CORPORATION 01' NEW YORK.

SYSTEM OF" ELECTRICAL. CONDUCTORS.

Application filed. November-14, 1924. Serial. No. 749,819&

Thisinvention relates to systems of electrical conductors and more particularly to improvements in elevated conductor systems.

The design of the supporting structure torany antenna system involves both electrical and mechanical eti'ects and in most cases leads to a compromise dictated by economic considerations. When metal supporting towers or poles are used",.the proximity of the metal structureto the antenna conductors serves to reduce the effective height of the antenna. Currents flowing between the ground and the antenna by Way of the towers or guy Wires hear more or less random phase relations to the current in. the member or members of the antenna proper, thereby introducingr losses and undesired directional effects. These losses and effects become particularly pronounced as the natural period, of. the towers approaches the period of the radio signal Placin r the towers beyond the intense electrical fie d of a of radiation of an antenna.

structures for the elevated conductors of the antenna. and as multiple down leads therefor.

Inother words, the metallic supporting towers or poles 0t an antenna are inconpo rated into the antenna whereby the currents present therein are caused to radiate useful rather than undesired energy. Certain loadingvcoils required in the multiple down leads of. an antenna are so positioned with respect thereto that the voltages generated in the coils may be reduced. and their construction simplified. These coils may be conveniently wound upon insulating devices that serve also to electrically separate the elevated conductors from direct contact with the supporting structures.

In the drawings, wherein like reference characters have been used to indicate like parts in the several figures: i

Fig. l is a plan view illustrating the arrangement of a multiple tuned antenna.

using the supporting masts as down leads.

Fig. 2 is a view in elevation illustrating a multiple tuned. antenna arranged in a manner dilferent from thatof Fig. 1.

F lg. 3 is a detailed view in prospective illustrating the method of supporting an antenna and loading coils therefor.

Fig. 4' illustrates a slightly different sup- The antenna illustrated in Fig. 11 C0nl prises elevated conductors arranged in the form, of a. triangle and supported by masts ortowers 10, 11 and 12 positimied at the apices of the triangle. The elevated conductors are arrangedto form cages 13, 14: and 15 suspendedbetween the masts or towers 10, l1 and 12 andcages 16 radiatingfrom the geometric centerof the tower system and so connected as to bisect the sides of the triangle formed by the cages 13, 1+1 and 15. The antenna conductors are at tached'to the masts 10, 11 and 12 by means ofstrain insulators 17.. y

Loading coils 18, 1.9 and 20 are positioned at or near the top of the towers 10, 11 and 12, respectively, and are connected between the antenna conductors and the masts at the apices of. the triangle.

The center oftlie antenna is connected to ground by a path including. the secondary porting arrangement for the system of conductors.

winding of a transformer 21, the primary winding of which may be connected to any source 22 of electrical waves.

The masts 10, 11 and 12 are connected to ground; for example, as illustrated in Fig. 2, and serve as down leads for theantenna The antenna is thus divided into av plurality of tuned sections formed by the inductances of the respective portions of the antenna conductors and their capacity to ground. By so utilizing the supporting towers as down leads and by placing the loading coils at the top rather than at the bottom of the towers as has been customary in the past, the eflectivc height of the antenna increased and the losses which would be otherwise introduced by the currents in the towers are prevented.

Moreover, the construction of the insulators may be simplified since they need not be designed to withstand the maximum voltage between elevated conductors and ground but need only withstand the voltage drop over the loading coil which may be made less than the maximum voltage by positioning the coils so that current antinodes occur at points remote therefrom.

In Fig. 2 the invention is illustrated as applied to a multiple tuned antenna of a type different from that illustrated in Fig. 1. The antenna of Fig. 2 comprises an elevated conductor 23 supported upon masts 24. The conductor 23 is provided with loading coils 25 connected between it and the respective masts. A source of waves 22 is coupled by means of the transformer 21 to the antenna conductor 23. The masts 24 are each connected to ground as illustrated. An auxiliary loading coil 26 is connected between the outer terminal of conductor 23 and ground.

The system shown in this figure functions in the same manner and has the same 'features and advantages as the system shown in Fig. 1. The masts 24 function as down leads for the elevated conductor 23, whereby other down lead conductors are eliminated and the efiicienc* of radiation from the antenna is increased by virtue of the absence of detrimental currents that would be present it down leads separate from the supporting structures were employed.

An added advantage of the arrangements illustrated in Figs. 1 and 2 resides in the fact that the construction of the masts is simplified by virtue of the reduction in the mechanical stresses in the system resulting from the elimination of the down leads normally provided which give added weight to the elevated conductors, necessitating increased provision for their support.

In Fig. 3 another method of supporting the elevated conductors of an antenna is illustrated. The conductors 27 are suspended by means of insulators 28 from the cross-arm of a grounded tower 29 and are connected to the tower 29 through loading coils 30. These coils are wound upon the insulators 28, respectively. By virtue of the fact that the antenna conductors 27 are connected to the mast 29, the voltage between the conductors and mast may be reduced to a small value represented by the drop in voltage in any instance across the coil winding connected therebetween. This results in an advantage in that the dielectric strength of the insulators 28 need not be as great as would otherwise be required and accordin ly the design of these insulators is simplified and their cost of construction is reduced.

In Fig. 4 the conductor 27 is shown mounted upon the insulator 28, which in turn is mounted upon the cross-arm3l. The winding of the choke coil 30 is supported upon the insulator 28 as illustrated in Fig. 3. While but one conductor is shown, it is to be understood that the antenna may consist of a plurality of conductors each supported as described above.

Although this invention has been illustrated and described in connection with certain embodiments consisting principally of antenna. systems, it is not to be limited by the specific disclosure, but only as indicated by the scope of the appended claims.

hat is claimed is:

1. A system of elevated antennae conducs tors, means for supportin said conductors, said means being connected to ground, and a loading coil connected between said conductors and said su porting means.

' 2. A system of e evated antennae conductors, a rounded supporting means therefor, means or electrically loading said conductors, said loading means being positioned at the top of said supporting means. I

3. A system of elevated antennae conductors, a rounded supporting means therefor, means or electrically loading said conductors, said means being connected between the top of said supporting means and said conductor.

4. A system of elevated conductors, conducting supporting means therefor connected to ground, means for electrically loading said conductors, said means being con nected between said supporting means and said conductors and positioned at the top of said supporting means.

5. A system of elevated conductors, rounded supporting means therefor, means i or insulating said conductors from said supporting means, and loading inductance for said conductors comprising coils wound upon said insulating means.

6. A system of extended elevated conductors, supporting means therefor attached thereto at separated points, individual loading inductances connected between said conductors and said supporting means, said supporting means being connected to ground.

III

5 for making electrical connection between said 7. An antenna comprising a plurality of sections of cage type conductors, a plurality of supports for said conductors, said supports being connected to ground, and means supports and said conductors comprising a plurality of loading coils.

S. An antenna which comprises a plurality of tuned sections, means for providing individual return leads to ground for each section said means acting also to so port said antennayand a loading coil includ ed in each of said return leads.

9. An aerial conductor, a mast for supsaid. conductor, and a loading inductance electrically connected to said mast and said conductor, said inductance comprising a conductor wound upon said insulator.

In witness whereof, I hereunto subscribe my name this 11th day of November A. D., 1924.

ARTHUR A. OSVVALD. 

